1. Field of the Invention
The present invention relates to a structure of a front fork which can effectively accommodate an oil filling operation for a front fork.
2. Description of the Related Art
In Japanese Patent Application Laid-open No. 8-270705 (patent document 1), there is disclosed an inverted type front fork apparatus which is constituted by a left tube assembly 1 and a right tube assembly 2, and which has a damper apparatus 14 built-in only in the left tube assembly 1. The right tube assembly 2 having no damper apparatus 14 built-in is structured, as shown in FIG. 2 thereof, such that a lower end portion of a suspension spring 13 is supported to an axle bracket 15, and an upper end portion is supported to a suspension piece 62 fixed to a support rod 61 via a washer 59 and a suspension collar 60. An upper end of the support rod 61 is screwed to a fork bolt 23.
A rebound stopper 64 is screwed to an upper end of the inner tube 12. The rebound stopper 64 is brought into contact with a bound stopper 63 at a time of maximum compression, whereby a compression stroke of the right tube assembly 2 is stopped. The rebound spring 65 is attached to the suspension piece 62. The rebound stopper 64 is brought into contact with the rebound spring 65 at a time of maximum expansion, whereby an expansion stroke is stopped.
Not being disclosed in patent document 1 mentioned above, four connecting holes 64b are formed in an outer periphery of a center hole 64a through which the support rod 61 is inserted, formed in the rebound stopper 64. An annular gap is formed between an outer periphery of the support rod 61 and an inner periphery of the center hole 64a of the rebound stopper 64, as shown in FIGS. 6 and 7 of the present application.
An oil filling procedure during assembly of the right front fork is executed such that the outer tube 11 is pressed down to the lowest end portion of the inner tube 12, the suspension spring 13 is fully expanded, and the rebound spring 65 is compressed between the suspension piece 62 and the rebound stopper 64. At this time, since some of four connecting holes 64b formed in the rebound stopper 64 are closed by a flat end coil portion on an end portion of the rebound spring 65, the oil filling work is carried out by inserting an oil filling nozzle 76 to one of the connecting holes 64b which are not closed by the end coil portion.
However, since some of the connecting holes 64b except the connecting hole to which the oil filling nozzle 76 is inserted are closed by the end coil portion, air within a lower chamber of the rebound stopper 64 is not easily released into the atmospheric air during the oil filling, i.e., air bleeding in the lower chamber can not be achieved. Accordingly, troubles such as excessive time is required for the oil filling, cleaning being required in the later step due to an overflow of the oil, and the like are created.